The present invention is a process for the preparation of hydrolyzable beta-cyanoalkylsilanes. More particularly, this invention is a process for the catalytic addition of silicon hydrides to .alpha.,.beta.-unsaturated olefinic nitriles to form .beta.-cyanoalkylsilanes. The present process employs a novel catalyst comprising an aminoorganosilane and a copper source. The catalyst may be provided to the process on a solid support.
Hydrolyzable .beta.-cyanoalkylsilanes prepared by the present process are useful for the production of polyorganosiloxanes containing the .beta.-cyanoalkyl substituent. The silicon-bonded .beta.-cyanoalkyl radical is extremely resistant to hydrolysis and cleavage under hot, humid conditions. Therefore, the .beta.-cyanoalkylsilanes find particular use in the preparation of polyorganosiloxanes which must be subjected to hot, humid conditions. The presence of the silicon-bonded .beta.-cyanoalkyl radical substituted on polyorganosiloxanes also tends to stabilize the polyorganosiloxanes against swelling induced by liquid hydrocarbons.
Bluestein, U.S. Pat. No. 2,971,970, issued Feb. 14, 1961, describes a process for preparing cyanoalkylsilanes which comprises reacting a hydrolyzable silicon hydride with an .alpha.,.beta.-unsaturated olefinic nitrile in the presence of a diamine, a tertiary amine and a cuprous compound selected from the class consisting of cuprous oxide and cuprous halides.
Bluestein, U.S. Pat. No. 2,971,972, issued Feb. 14, 1961, describes a process for adding phenyldichlorosilane to acrylonitrile in the presence of a catalyst composition consisting essentially of a trialkylamine and a cuprous compound selected from the group consisting of cuprous halides and cuprous oxide.
Svoboda et al., Collection Czechoslov. Chem. Commun. 38:3834-3836, 1973, describe binary systems of a copper compound (Cu.sub.2 O, CuCl, or Cu(acac).sub.2) and an isocyanide (tert-butyl or cyclohexyl isocyanide) as effective catalysts for hydrosilation of acrylonitrile by trichlorosilane and methyldichlorosilane.
Rajkumar et al., Organometallics 8:550-552, 1989, describes a two-component catalyst, consisting of cuprous oxide and tetramethylethylenediamine, that promotes .beta.-hydrosilylation of acrylonitrile.